Lyra passes out on her way home one night, but when she wakes up she finds herself in a strange realm of fire, ash, and creatures that she could only refer to as demons. Before she meets what she assumes is her end, she is saved by a group of bipedal creatures that take her to their master, someone named Illidan Stormrage. There she learns what the bipedal creatures are preparing for and is offered a choice; either join them or return to her home.

The problem, she discovers, is that there is another displaced pony wandering the land of Azeroth; so she has to choose between a rock and a hard place. She only hopes that she doesn't regret her choice after making it.

(World of Warcraft; Legion crossover with MLP)
(Part of the Universe 13 story series, though reading the other stories is not required)

First of the Savage Skies series.
After running afoul of timberwolves in the Everfree Forest, Fluttershy is saved by a mysterious young colt with a most unusual and disturbing feature. Realizing that he is alone, without anyone else to care for him, Fluttershy realizes that she must try to bring this lonely foal out of the forest and give him a life of love and friendship. The problem is that this colt's...unique qualities have made him more than a few enemies, including some who are closer to home than Fluttershy realizes.

Now with a sequel: The Promise of a New Day.
Now with a TV Tropes page.

How would things be different if Twilight had never made it to Ponyville? Twilight Sparkle finds out just how different things could be when she is forced to travel to her own past while chasing down a mystery; a plot to erase Princess Twilight Sparkle from history.

Landing in a time just weeks after the one thousandth Summer Sun Celebration, she finds a world shrouded in an eternal night, where the Elements of Harmony were never recovered. Can she fix the things that should have, but didn't happen? Or is this Equestria destined to head down a different path?

Chinese Translation by Hell Organist

Things are hard in Ponyville for Fluttershy and Discord; mainly because of Discord. But when magic starts to go on the fritz and eventually starts failing altogether, it's up to the main six and the Draconequus to find out what's causing it and, more importantly, how to fix it.

This would be a lot easier if anypony trusted the King of Chaos to begin with, but with bigger problems on the horizon, some things will have to wait to be dealt with. Like trust. Or loyalty. Or friendship.

Of course, sometimes what we think isn't important to deal with right now, is exactly what's needed to prevent things from getting far, far worse.

Trixie Lulamoon has led a hard life, especially after the events of her magic duel with Twilight Sparkle. Now trying to piece herself back together, can she learn the meaning of friendship from her first real friend, Maud Pie? What kind of events will happen between these two ponies? Can Trixie get through to Maud's heart? Will Trixie learn the true meaning of Friendship?

Special thanks to Crow for all the help.

There is a direct sequel up already called Heart of Stone: Recovery Light. Check it out here!